Observation or sighting system

ABSTRACT

An observation or aiming system for a self-propelled vehicle is described. The system includes a post pivoting about a bearing axis (Ag) relative to the vehicle. The post carries a body for an optical block and a thermal camera which are mounted to pivot about an elevation axis (As) perpendicular to the bearing axis (Ag). The body and the thermal camera are disposed symmetrically relative to the bearing axis (Ag). The system also includes a radar channel having a radar transmitter unit mounted on the body, a radar detection unit mounted on the body close to the bearing axis (Ag) and concentration means situated in the body for concentrating radar waves on the radar detection unit. The optical block, the thermal camera, and the radar channel are secured so as to always have the same orientation in elevation and in bearing, and thus the same observation direction.

FIELD OF THE INVENTION

The present invention relates to observation and aiming systems.

More particularly, it relates to improvements to optoelectronicpanoramic observation systems mounted on vehicles, and in particular oncombat helicopters.

BACKGROUND OF THE RELATED ART

Systems of this type are already known, in particular gyrostabilizedsights and devices for helicopters and for armored vehicles manufacturedby one of the Applicant companies.

Conventionally, such a system comprises an optical block for anobservation and aiming channel in the visible range (purely opticalchannel), together with various sensors such as an infrared camera, atelevision camera, and a laser, in particular for night vision,deviation measuring, range finding, and/or target designation.

The line of sight of those various means is mounted to pivot inelevation and in bearing relative to the structure of the vehicle.

Presently known observation and aiming systems are particularly welladapted to observation, reconnaissance, identification, and also firing,and in general, to most military missions.

Nevertheless, certain military situations can require action to be takenvery far ahead of armed forces deep into the enemy disposition.

A mission to penetrate into a zone controlled by the enemy, requiresinter alia, the ability to detect random threats that were unknown whenpreparing for the mission and that can appear while it is in progress.

To succeed with such a mission, both observation and identification, aspresently possible using manually-steered optronic means withperformance limits that are rapidly reached as a function of conditionsof use, are functions that are insufficient. Other functions need to beadded to them, such as all-weather watch and detection so as to enablethe crew of the vehicle (helicopter, land vehicle, . . . ) to be able toundertake bypassing and evasive maneuvers early enough to avoid alertingthe opponent and carry on with the mission.

Unfortunately, present observation and aiming systems are unsuitable forall-weather watch or detection.

Thus, although infrared detection provides good resolution, its rangeand contrast are disturbed by humidity and bad weather conditions.

SUMMARY

An aim of the invention is to propose an observation and aiming systemenabling that drawback to be mitigated.

The invention provides an observation or aiming system for a vehicle,the system comprising an optical block for observation and/or detectionusing a channel in the visible range and sensors for night vision and/ordeviation measuring and/or range finding and/or target designation, saidoptical block and said sensors being mounted to pivot about at least oneaxis relative to the vehicle, the system being characterized in that itfurther includes means for detection and/or observation in themillimeter wave range, having transmit and receive means situated closeto the optical unit and the sensors, and pivoting about at least oneaxis together with said optical block.

It will be understood that such a system continuously makes available animage in the visible range and an image in the millimeter wave range,both corresponding to the same observation direction—and optionallysuperposed on same-direction images taken by the sensors, such as a CCDcamera covering the visible and the infrared spectrum, and a thermalcamera covering the far infrared.

Such a system thus makes it possible to perform analysis over a broadrange of wavelengths.

Advantageously, the transmit and receive means in the millimeter waverange are carried by a body in which there are received optical meansand which is mounted to pivot about an elevation axis on a post which isitself mounted to pivot relative to the carrier vehicle about a bearingaxis.

Such a configuration makes it possible to provide a structure of optimumcompactness.

BRIEF DESCRIPTION OF THE DRAWINGS

Other characteristics and advantages of the invention appear from thefollowing description. The description is purely illustrative andnon-limiting. It should be read with reference to the accompanyingdrawing, in which:

FIG. 1 is an exploded perspective view of a sight constituting apossible embodiment of the invention; and

FIG. 2 is a section view of a detail of the FIG. 1 sight.

DETAILED DESCRIPTION

The gyrostabilized observation and aiming system shown in FIGS. 1 and 2comprises a structure 1 fixed to the vehicle either directly or via asuspension, together with a base 2 received on the structure 1.

Inside the vehicle, the base 2 carries an optical unit 4 together with aretractable eyepiece arm or telescope 3, of conventional structure.

On the other side of the structure 1, the base 2 carries a post 5forming a support for the means constituting various observation anddetection channels. This post is rotatably received on the base 2 aboutthe relative bearing axis Ag of the system.

The post 5 carries an optical block body 6 and a thermal camera 7 whichare disposed in diametrically opposite positions about the axis Ag.

The body 6 and the thermal camera 7 are both mounted to rotate on thepost 5 about an axis As which is perpendicular to the axis Ag and whichdefines the axis of rotation. in elevation for the various observationand detection means of the system.

The body 6 serves as a mechanical support for numerous elements.

In particular, it carries an optical block 9 and a radar detection unit10.

The radar detection unit 10 is fixed on the body 6 via a leg 10 a, ofthe unit 10. The leg 10 a, is received in a complementary housing 6 a,in the top face of the body 6.

The optical block 9 is received together with a radar transmitter unit11 and a television camera 12 fixed on said block 9 in a housing of thebody 6 on the elevation axis As.

The optical block 9, the unit 11, and the camera 12 are protected insidethe body 6 by a cover 13 fixed on the main body of the body 6.

The cover 13 has at least one porthole 13 a, through which the opticalblock 9 and the camera 12 see the environment of the vehicle.

In an embodiment shown more particularly in FIG. 2, the body 6 alsocarries an external concave reflector 14 which co-operates with aninclined plane reflector 15 to concentrate millimeter waves reflectedfrom the environment of the vehicle onto a detector 16 of the radarreceiver unit 10.

Other millimeter wave concentration methods could be used such as aplurality of reflectors, lenses, and multiple sources, which methods canbe used singly or in combination.

The millimeter wave reflector 14 is oriented so that its direction ofobservation coincides with that of the optical block 9 and with that ofthe cameras 7 and 12.

The various elements of the above-described system that are situatedoutside the structure 1 of the vehicle are sheltered within a protector17 that is fixed via a plate 17 a, to the post 5 that is rotatable inbearing relative to the structure 1.

The protector 17 has a radome 18 located in front of the millimeter wavereflector 14 and through which millimeter wave observations areperformed. Visible and infrared observations, together with laserrangefinding and/or laser target-designation take place through openingsformed in the protector 17 on either side of the radome 18.

With a disposition of the type described above, the observation means inthe visible range (purely optical means), in the infrared range, and inthe millimeter wave range are situated in the immediate vicinity of oneanother and always have the same orientation in elevation and bearing.

The various images picked up by these different channels are stabilizedand centered on a common direction which is steerable in elevation andin bearing. This orientation direction is known accurately relative tothe direction in which the vehicle is pointing and also relative to thedirection in which it is moving. These various centered images can havethe same field of observation or they can have fields of observationthat are different or variable, depending on the functions used: keepingwatch, searching, or identification.

Having the optical and millimeter wave sensors sharing a commonstabilization support improves knowledge concerning the positions ofobserved objects compared with using sensors mounted on distinctstabilization supports.

Advantageously, the system also includes means that operate as afunction of watch-keeping and/or searching to control automatically andwithout intervention from the observer the optical means constitutingthe block 9, the sensors constituting the camera 12 and the thermalcamera 7, and the millimeter wave means, so that their common directionof observation scans the environment of the vehicle automatically inelevation and/or bearing, and in particular does so with desiredamplitudes and speeds.

In a variant, in order to increase the scanning independence of themillimeter wave means, they are not only caused to move mechanicallyabout the elevation axis and the bearing axis together with the body 6on which they are fixed in association with the optical block and thesensors, but they also scan the millimeter wave beam electronically inconventional manner. Such scanning can be performed in elevation and/orin bearing relative to a “canonical” position which is the positionoccupied by the millimeter wave beam when its axis is oriented in thesame direction as the optical axes of the optical block and of thesensors.

The images taken by the various channels are used on board the vehiclein such a manner that the weaknesses and limits of one or other of thevarious channels are compensated by the advantages of the others.

Thus, whereas infrared observation suffers from range and contrast thatare severely degraded by humidity, mist, fog, or rain, millimeter wavesare insensitive to such conditions. In particular, they penetrate fog,whereas fog is opaque in the infrared.

In addition, the natures of the parameters detected by the infrared andradar apparatuses are different. The infrared device detects naturalemission from bodies, i.e. their emissivity, whereas the active radardevice is based on the reflectivity thereof. Such reflectivity isparticularly high for objects made of metal.

Advantageously, the system includes processing and display means whichenable an operator to view either each of the various images from thedifferent channels independently from one another, or else an image thatis combined and enriched using the images from the various channels.

In particular, a synthetic image can be presented on a monitor screen 19situated close to the eyepiece arm 3 or incorporated therein, e.g. byintegrating pertinent data coming from the various channels.

The system described above can be used in various modes of operation.

In particular, in a main operating mode, the radar channel and theinfrared channel are used in complementary manner to operate inwatch-keeping or detection mode.

Also, the radar unit 10 can be used to give access to speed measurementsby Doppler analysis or to give access to distance measurements.

The various observation channels may also be used in complementarymanner to provide operators inside the vehicle with tactical analysis ofthe field of operation, or assistance in piloting, in avoidingcollision, and in navigation, or indeed in monitoring the weather.

They can also be used to provide assistance in fire control inidentification mode, assistance in automatic tracking, in targetdesignation/illumination, or in deviation measuring.

The observation or aiming systems of the invention are advantageouslyused in combat helicopters and land vehicles.

What is claimed is:
 1. An observation or aiming system for a self-propelled vehicle, comprising: a post pivoting about a bearing axis (Ag) relative to the vehicle, the post carrying a body for an optical block and a thermal camera which are mounted to pivot about an elevation axis (As) perpendicular to the bearing axis (Ag), wherein the body and the thermal camera are disposed symmetrically relative to the bearing axis (Ag); a radar channel including a radar transmitter unit mounted on the body and a radar detection unit mounted on the body close to the bearing axis (Ag); and concentration means situated in the body for concentrating radar waves in the millimeter wave range on the radar detection unit including a plurality of reflectors arranged in a particular relationship and an electronic scanning mechanism, and is associated with at least one lens; wherein the optical block, the thermal camera, and the radar channel are secured so as to always have the same orientation in elevation and in bearing, and thus the same observation direction.
 2. A system according to claim 1, wherein the concentration means comprise a concave reflector and an inclined plane reflector.
 3. A system according to claim 1, wherein the concentration means are situated between the optical block and the thermal camera.
 4. A system according to claim 3, wherein the system includes a protector which includes a radome covering the concentration means and which also includes openings situated either side of the radome respectively facing the optical block and the thermal camera.
 5. A system according to claim 1, wherein the millimeter wave concentration means include one or more lenses optionally associated with one or more reflectors.
 6. An observation system according to claim 1, further comprising image processing and display arrangement which is configured to enable an operator to view images provided by the optical block, the thermal camera and the radar channel independently of one another.
 7. A system according to claim 1, further comprising means for controlling the orientation of the optical block, the thermal camera and the concentration means so as to cause their common observation direction to scan automatically in at least one of elevation and bearing. 